Isopods Cymothoidae ectoparasites of fish from the Amazon

Abstract Most freshwater species of Cymothoidae are distributed in South America. They have mainly been recorded in the eastern and western regions of the Amazon River basin. However, in this ecosystem, the biodiversity of this group may be greater if the entire Amazon basin is considered. In this regard, the aim of the present study was to provide an updated list of isopod species of the family Cymothoidae that are found in fish in the Brazilian Amazon region and to report on new fish host occurrences and expanded geographical distributions for cymothoid isopods that parasitize fish in the southwestern Brazilian Amazon region. The parasites found in fish specimens were collected, fixed and identified later. We found eight species of Cymothoidae parasitizing different host fish species in the southwestern Amazon region. However, we found 14 species of Cymothoidae throughout the Brazilian Amazon region. Three additional species are thus reported here, which increases the number of species of Cymothoidae in this region to 17. These additional species are also new records for Brazil. Therefore, this study has contribute to expand the knowledge about the distribution and diversity of Cymothoidae in the Amazon basin.

摘要：绝大多数缩头水虱科（Cymothoidae）的淡水物种分布于南美洲，目前该类群的记录主要集中于亚马逊河流域的东部与西部区域。然而若覆盖整个亚马逊流域进行考量，该类群的生物多样性或更为可观。有鉴于此，本研究旨在更新巴西亚马逊地区鱼类宿主所携带的缩头水虱科等足类物种名录，并报告巴西西南亚马逊地区寄生鱼类的缩头水虱科等足类的新宿主记录与扩张后的地理分布范围。研究人员采集鱼类标本中的寄生虫，经固定后开展后续物种鉴定工作。本研究在西南亚马逊地区共发现8种寄生于不同宿主鱼类的缩头水虱科物种；而在整个巴西亚马逊区域内，共记录到14种缩头水虱科物种。本次新增3个物种记录，使该区域缩头水虱科物种总数增至17种，上述新增物种同时为巴西境内的新记录物种。综上，本研究有助于拓展学界对亚马逊流域缩头水虱科物种分布与多样性的认知。